Hi all. NB. ---------------------------------------------------------- NB. Vector function NB. vf(x,y,z) = (x^2*y^3; 2*x^2*y^3 + 4*y*z^2; y*z^2) NB. ---------------------------------------------------------- fv=:3 : 0 'a b c'=.y >((*:a)*b^3); (((2*(*:a)*b^3))+(4*b**:c)); (b**:c) )
NB. ---------------------------------------------------------- NB. Jacbian of vector function NB. ---------------------------------------------------------- det=:-/ .* Det=:det@ jac=:D.1 Det NB. -------------------------------------------------------------------- NB. Jacbian of vector function fv at point (1;2;3) NB. -------------------------------------------------------------------- fv jac 1 2 3 Answer: _5.1159089799171479e_6 Must be 0 i.e accuracy of derivative calculations: 6 correct decimal digits (float32) In what way to make better derivative calculation accuracy? ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
